Panasonic sa ch72

Page 1

ORDER NO. MD9502014C2

ervice Manual

@GDMPABT

DIGITAL AUDIO

Remote
Control .
Transmitter

SA

I {SB-CH72

TAPE SECTION : AR300 MECHANISM SERIES
CD SECTION

I Specifications

I Amplifier Section
1 kHz continuous power output,

both channels driven 2 x 35 W (THD 1%, 6(1)
RMS 2 x 47 W (THD 10%, 69)
Total harmonic distortion

Halt power at 1 kHz 0.07 % (69)
Frequency response

CD, AUX 45 Hz A 20 kHz (4 dB)
Inputsensitivity and impedance

AUX 250 mV, 28 k9
Load impedance 6 Q

I FM Tuner Section

Frequency range 87.5 7 108.0 MHz
Sensitivity 23.3 dBf
Total harmonic distortion

MONO 0.3%

STEREO 0.5%
SIN MONO 60 dB
Image rejection at 98 MHz 35 dB
Stereo separation at 1 kHz 35 dB

Antenna terminal(s) 759 (unbalanced)

I AM Tuner Section

Frequency range
MW 522 i 161 1 kHz
LW 144 - 288 kHZ
Sensitivity (tor 500 mW)
MW (at 999 kHz) 250 uV/m
LW (at 252 kHz) 500 pV/m
Notes :

1. Specifications are subject to change without notice.
Weight and dimensions are approximate.
2. Total harmonic distortion is measured by thedigital spectrum analyzer.

*2

Dolby noise reduction manufactured under license from

Dolby Laboratories Licensing Corporation.
"Dolby" and the double-D symbol are trade marks of Dolby
Laboratories Licensing Corporation.

Panasonic®

MASH un-

min a... none mama

SBaCH72

: RAE0113Z TRAVERSE DECK SERIES

CD Stereo System

SA- CH72

Colour
(K) . . Black Type
Area
Suffix for
Model No. Area Colour
7 (E) Continental Europe
(EB Great Britain (K)
(EG) Germany and Italy
System Music Center Speaker
SC»CH72 E SA-CH72 E
SB-CH72 E
SC-CH72 EB SA-CH72 EB
(made in PAES)
SC-CH72 EG SA-CH72 EG

I Cassette Deck Section

Tracksystem 4 track. 2 channel
Heads

Playback Solid permalloy head (Rotary head)

Record/playback Solid permalloy head (Rotary head)

Erasure Double gap ferrite head
Motor DC servo motor
Recordingsystem AC bias 100 kHz
Erasing system AC erase 100 kHz
Tape speed 48 cm/s (17/3 ips)
Frequency response

NORMAL 40 Hz - 14 kHz (+3 dB, -6 dB)

CrOz 40 Hz- 14 kHz(+3 dB, -6dB)
SIN (CrO2 type)

Dolby NR off 52 dB (A»WTD)

Dolby NR on 61 dB (CClR)
Wow and flutter 0.1% (WRMS)

Fast forward and rewind time
Approx. 1 10 seconds with 0-60 cassette tape

I CD Changer Section
Sampling frequency 44.1 kHz
Decoding 16 bit linear
Beam source/wavelength Semiconductorlaserflso nm
Number cfchannels Stereo
Frequency response 20 Hz - 20 kHz (+1 , 72 dB)
SIN

CD UNlT OUT 95 dB (JIS.A)
Wow and flutter Below measu rable limit
Digital filter 4 is
DIA converter MASH (1 bit DAC)
I General
Power consumption 120 W

AC 50 Hz, 230 v (E, EG)
AC 50 Hz, 230 7240 v (EB)
Dimensions (W x H x D) 270 x 345 x 327 mm
Weight 8.2 kg

*1 MASH is a trademark or NTT.

© 1995 Matsushila Electronics (S) Pte. Ltd.
All rights reserved. Unauthorized copying and
distribution is a violation of law.

Power supply

Page 2

SA-CIfl72

l
A WARNING i
This service infomation is designedforexperiense repairtechnicians onlyand is notdesigned foruse by the general public. ltdoes not contain warnings I
orcautions toadvise non-technical individualsof potential dangers in attempting to service a product. Products powered by electricity should be serviced
or repaired only by experienced professional technicians. Any attempt to service or repairthe product orproducts dealt with in this service information
by anyone else could result in serious injury or death.

I Contents

BEFORE REPAIRANDADJUSTMENT ...................
HANDLING PRECAUTIONS FOR TRAVERSE DECK
PROTECTION CIRCUITRY .........
PRECAUTIONOFLASER DIODE
CAUTION FOR AC MAINSLEAD.
ACCESSORIES.

WIRING CONNECTION DIAGRAM,
BLOCKDIAGRAM .............
PRINTED CIRCUIT BOARD.
SCHEMATIC DIAGRAM...
TROUBLESHOOTING GUIDE ......................
MECHANISM PARTS LOCATION (RAA0372
CONNECTION 8.. MECHANISM PARTS LOCATION (RAA0373
LOCATION OF CONTROL MECHANISM PARTS LIST .......
OPERATION CHECKS& MAIN COMPONENT REPLACEMENT .8 ~14 CD LOADING UNIT PARTS LIST.
DIGITALSERVO SYSTEM ..................... ....15 CD LOADING UNIT PARTS LOCATION.
MEASUREMENTS AND ADJUSTMENTS. 16 ~ 18 CABINET PARTS LOCATION.
GENERAL INSPECTION ........................ REPLACEMENTPARTS LIS
DISPLAYFUNCTIONSOFAUTOMATICALLY-ADJUSTEDRESULTS RESISTORS&CAPACITORS..
SELF-DIAGNOSTICDISPLAYFUNCTION 21 &22 PACKING MATERIALS&ACCESSORIES
TERMINALFUNCTIONOFICS ................. 23~25 PACKAGING ..........................................
TERMINAL GUIDE OF ICS, TRANSISTORS AND DIODE

I Before Repair and Adjustment

Disconnect AC power, Discharge both Power Supply Capacitors 0522 and 0523 through a 109, SW resistor to ground.
DO NOT SHORT-CIRCUIT DIRECTLY (with a screwdriver blade, for instance), as this may destroy solid state devices.
After repairs are completed, restore power gradually using a variac, to avoid overcurrent.

Current consumption at 230V ( 240V for EB area), 50 Hz in NO SIGNAL mode should be less than 250mA.

I Handling Precautions for Traverse Deck Var'ab'emiswr

(Do not turn)
The laser diode in the traverse deck (optical pickup) may break down due to
potential difference caused by static electricity of clothes or human body.
So, be careful of electrostatic breakdown during repair of the traverse deck K
(optical pickup). Lens (Do not touch)

/0pticat pickup

- Handling of traverse deck (optical pickup)

1.Do not subject the traverse deck (optical pickup) to static
electricity as it is extremely sensitive to electrical shock. FPC board

2.To prevent the breakdown of the laser diode, an antistatic (Handleifcamtullw
shorting pin is inserted into the flexible board (FPC board).
When removing or connecting the short pin, finish the job in as é
short time as possible. /

3.Take care not to apply excessive stress to the flexible board _.
(FPC board). as sure to short this position

4.Do not turn the variable resistor (laser power adjustment). It has (Use the shorting pin or clip) Clip snorting pin
already been adjusted. """"

l

- Grounding for electrostatic breakdown prevention
1.Human body grounding
Use the anti-static wrist strap to discharge the static
electricity from your body.
2.Work table grounding
Put a conductive material (sheet) or steel sheet on the
area where the traverse deck (optical pickup) is placed,
and ground the sheet.
Caution :
The static electricity of your clothes will not be grounded
through the wrist strap. So, take care not to let your clothes
touch the traverse deck (optical pickup).

Wrist strap
(Antistatic bracelet)

1MB

Iron plate or some metals
to conduct electricity